Abstract: A method and radio interface having a reconfigurable massive multiple input-multiple output (MIMO) array system for energy efficient communications are provided. According to one aspect, a method includes, for a beam direction, one of activating and deactivating each of a plurality of radio frequency (RF), branches based at least in part on the beam direction and at least one power constraint, each RF branch being in electrical communication with at least one antenna of an antenna array of the radio interface. The method also includes, for the beam direction, configuring at least one switch of a plurality of switches positioned between antenna elements to selectively affect a mutual coupling between at least two antenna elements of the antenna array that are in electrical communication with deactivated RF branches, the configuring being based at least in part on the beam direction.

Abstract: A method and network node for diversity-aware truncated layer selection for low complexity beamforming are provided. According to one aspect, a method in a network node includes receiving a precoder rank indication, and selecting one of two precoders of different ranks one of cyclically and randomly when the indicated precoder rank is greater than 1.

Abstract: A method and network node for spatial audio assisted radio frequency (RF) beamforming for millimeter wave and terahertz communications in safe mode are disclosed. According to one aspect, a method in a network node includes triggering a wireless device (WD) to transmit at least one acoustic pulse, the triggering being prior to entering a safe mode of operation. The method also includes determining a direction of arrival of the at least one acoustic pulse received from the WD via the microphone array. The method further includes determining an RF beam for communication with the WD based at least in part on the determined direction of arrival. Transmission to the WD may occur on the determined RF beam.

Abstract: A method, system and apparatus are disclosed for downlink out-of-band interference mitigation. In one embodiment, a network node is configured to perform out-of-band (OOB) null steering and in-band null steering toward at least one direction; and use a constant amplitude precoder to align at least one radiation pattern associated with the OOB and in-band null steering. In one embodiment, a method implemented in a network node includes performing out-of-band, OOB, null steering and in-band null steering toward at least one direction; and using a constant amplitude precoder to align at least one radiation pattern associated with the OOB and in-band null steering.

Abstract: A network node is configured to receive and/or estimate respective precoder information for a plurality of wireless devices. A respective orthogonal projection matrix is determined for each of the plurality of WDs based at least in part on the precoder information of all other WDs of the plurality of WDs. A respective modified precoder matrix is determined for each of the plurality of WDs based at least in part on the respective orthogonal matrix and precoder information for each WD of the plurality of WDs. A composite precoder matrix is determined based at least in part on the modified precoder matrices for each of the plurality of WDs. A transmission beam shape is then determined for use in transmission to at least one of the plurality of WDs based on the composite precoder matrix.

Abstract: A method of operating a radio network node in a wireless communication system includes adaptively limiting effective isotropically radiated power, EIRP, of downlink signals transmitted by the radio network node on different physical channels. Radio network nodes that adaptively limit EIRP of downlink signals transmitted by the radio network node on different physical channels are also described.

Abstract: A method and network node for management of beams radiated by a phased array antenna of a network node to comply with regulatory or other constraints are provided. According to one aspect, a network node is configured to selectively transmit radio frequency beams in a plurality of directions on a plurality of layers to a plurality of wireless devices. The network node includes processing circuitry configured to direct and beams to a first set of directions while suppressing energy radiated in a second set of directions according to algorithms that modify a precoder to achieve a distribution of radiated energy without computationally burdensome optimization algorithms.

Abstract: According to one or more embodiments, a network node configured to communicate with a wireless device is provided. The network node includes processing circuitry configured to: receive multilayer feedback; determine a beamformer for transmission of a first quantity of transmission layers where the beamformer is based at least on information, in the multilayer feedback, that is associated with a second quantity of transmission layers, where the first quantity of transmission layers is a less than the second quantity of transmission layers; and cause the transmission using the beamformer.

Abstract: A network node configured to communicate with a plurality of wireless devices is provided. The network node includes processing circuitry configured to: receive partial Channel State Information, CSI, from each of the plurality of wireless devices; determine a first plurality of precoders based at least in part on the partial CSI received from each of the plurality of wireless devices where each precoder of the first plurality of precoders is associated with a respective one of the plurality of wireless devices; determine a second plurality of precoders based at least in part on the first plurality of precoders; and optionally cause multiple-user multiple-input multiple-output, MU-MIMO, transmission to the plurality of wireless devices based at least in part on the plurality of second precoders.

Abstract: A network node is configured to receive and/or estimate respective precoder information for a plurality of wireless devices. A respective orthogonal projection matrix is determined for each of the plurality of WDs based at least in part on the precoder information of all other WDs of the plurality of WDs. A respective modified precoder matrix is determined for each of the plurality of WDs based at least in part on the respective orthogonal matrix and precoder information for each WD of the plurality of WDs. A composite precoder matrix is determined based at least in part on the modified precoder matrices for each of the plurality of WDs. A transmission beam shape is then determined for use in transmission to at least one of the plurality of WDs based on the composite precoder matrix.

Abstract: Methods, network nodes and wireless device for setting an electrical tilt of an antenna array toward a distribution of wireless devices are disclosed. According to one aspect, a method includes for each of at least one sector of an area covered by the antenna array, determining a function of precoding matrix indicators, PMIs, received from a plurality of WDs in the sector. The method includes determining a current electrical tilt angle of the sector based on the function of PMIs. The method further includes comparing a difference between the current electrical tilt angle of the sector and a previously determined electrical tilt angle of the antenna array to a first threshold, and setting the electrical tilt angle of the antenna array based on the comparison.

Abstract: Methods, network nodes and wireless device for setting an electrical tilt of an antenna array toward a distribution of wireless devices are disclosed. According to one aspect, a method includes for each of at least one sector of an area covered by the antenna array, determining a function of precoding matrix indicators, PMIs, received from a plurality of WDs in the sector. The method includes determining a current electrical tilt angle of the sector based on the function of PMIs. The method further includes comparing a difference between the current electrical tilt angle of the sector and a previously determined electrical tilt angle of the antenna array to a first threshold, and setting the electrical tilt angle of the antenna array based on the comparison.

Abstract: A user equipment (UE) may compute uplink power control levels as a function of a downlink signal to noise ratio (SNIR). For example, the UE may determine an uplink transmit power level by summing a full power control (FPC) transmit power level, a product of a first adjustment factor (?) and the downlink SNIR, and a negative of a second adjustment factor (?2) when the product of the first adjustment factor (?) and the downlink SNIR is greater than or equal to the second adjustment factor (?2). A UE may also compute an uplink power control level as a function of target and/or current interference levels associated with neighboring base stations. A UE may also iteratively reduce a transmit power level until an interference level experienced by a neighboring base station has fallen below a threshold.

Abstract: In methods of operating a relay station in a multi-hop wireless relay network, the relay station in communication with a superordinate station and a subordinate station, a downlink transmission to/from the superordinate station is transmitted/received at a first frequency. An uplink transmission to/from the subordinate station is transmitted/received at a second frequency. Communications between the relay station and the superordinate station may be scheduled using frames, each frame including a downlink portion at the first frequency, and an uplink portion at the second frequency. The downlink portion includes first and second downlink subframes for communication between the superordinate station and first and second pluralities of stations, respectively. The uplink portion includes first and second uplink subframes for communication between the superordinate station and the first and second pluralities of stations, respectively.

Abstract: A wireless network includes a base station and a relay station for extending wireless coverage of the base station. Downlink data is sent by the base station and relayed through the relay station to a mobile station, where the downlink data is associated with a preamble that is sent directly from the base station to the mobile station. A transmit power of the relay station is adjusted for transmitting the downlink data from the relay station to the mobile station to reduce a difference between a first power level of the preamble received at the mobile station and a second power level of the downlink data received at the mobile station. The uplink transmit power of the mobile station for the data sent to the relay station is adjusted to compensate for the difference in path loss from mobile station to base station and mobile station to relay station and to compensate for the difference in noise_plus_interference level at relay station compared to that of the base station.

Abstract: A user equipment (UE) may compute uplink power control levels as a function of a downlink signal to noise ratio (SNIR). For example, the UE may determine an uplink transmit power level by summing a full power control (FPC) transmit power level, a product of a first adjustment factor (?) and the downlink SNIR, and a negative of a second adjustment factor (?2) when the product of the first adjustment factor (?) and the downlink SNIR is greater than or equal to the second adjustment factor (?2). A UE may also compute an uplink power control level as a function of target and/or current interference levels associated with neighboring base stations. A UE may also iteratively reduce a transmit power level until an interference level experienced by a neighboring base station has fallen below a threshold.

Abstract: A method of operating base station includes determining a first transmit power of a user equipment (UE), which includes determining a serving base station receive power, determining a path loss of the UE to the base station, determining a downlink signal to noise and interference ratio (SNIR) at the UE, and forming the first UE transmit power. Forming the first UE transmit power comprises summing the serving base station receive power, the path loss of the UE to the base station and the downlink SNIR. The method further includes instructing the UE to transmit at the first UE transmit power.

Abstract: In accordance with an embodiment, a method of operating a base station configured to communicate with a relay station includes allocating resources to the relay station. Allocating resources includes receiving feedback data from the relay station and scheduling resources to the relay station based on feedback data. Feedback data includes a total buffer size of the relay station and a number of user devices.

Abstract: A wireless network includes a relay station (RS) for extending wireless coverage of a base station. Data is sent by the base station and relayed through the RS to a mobile station (MS), where the data is associated with a preamble that is sent directly from the base station to the MS. A transmit power of the RS is adjusted for transmitting the data from the RS to the MS to reduce a difference between a first power level of the preamble received at the MS and a second power level of the data received at the MS. The uplink transmit power of the MS for the data sent to the RS is adjusted to compensate for the difference in path loss from MS to base station and MS to RS and to compensate for the difference in noise_plus_interference level at RS compared to that of the base station.

Abstract: A method selects a path for forwarding a data packet in a wireless communication system. A system capacity versus delay impact curve is calculated for a direct path to mobile station. The direct path has a capacity cost based on communication quality of a direct link between a base station and the mobile station. This curve is shifted by a predetermined time corresponding to an additional delay over a relay path to produce a projected capacity curve for the relay path having a second capacity cost determined according to a combined measure of signal quality of multiple links in the relay path. The second capacity cost is multiplied by a capacity cost ratio to produce a relay capacity curve. The direct path or the relay path is selected based on a comparison of the system capacity versus delay impact curve and the relay capacity curve according to a QoS requirement.